<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>伪元素选择器 before</title>
    <style>
    p::before{
        content: 'CSS';
    }
    </style>
</head>

<body>
    <!-- <p><span>css</span> 珠峰培训</p> -->

    <p>珠峰培训</p>
</body>

</html>